Bond's Vesper

"This is the version of the martini that Bond orders in Casino Royale. Make it like Bond: 'I never have more than one drink before dinner. But I do like that one to be large and very strong and very cold and very well made.'"

Directions

Pour gin, vodka, and Lillet over ice. Shake or stir (remember, Bond doesn't give a damn anymore!), then strain into a martini glass. Garnish with lemon twist. Enjoy, preferably while dressed in a tux and betting the Crown Jewels at the poker table.

Not exactly Bond's Vesper.
The original recipe called for 100 proof Vodka and 94 proof Gin. Over the last 40 years distillers have, generally, lowered the proofs of their liquor.
If you really want the taste, and kick, of the original, use Stoly 100 and Tanqueray Gin.
Then as Matt noted in his review, use Lillet Blanc with a few drops of bitters.

This is so elegant, once you have gathered all ingredients: Lillet Blanc, Gordon's Vodka, Gordon's Gin, shaken! Lemon twist. Better be sure you are sitting down. Fireplace helps. BTW, you can keep it in the freezer pre-mixed for really tough weeks. Life is good.